I recommend using a study technique called "circular review." I used the PM-Prepcast materials and PMBOK guide in combination with Head First PMP from Amazon. I would do a knowledge area one day with PM-Prepcast and the PMBOK guide on one day, then the next start the next knowledge area with PM-Prepcast/PMBOK and review the previous day's material in Head First PMP including doing all of the written exercises.
Simply put, there is no "easy" path to certification. You have to not just know the material but be able to apply the material to various situations that you get with each question. That means you must understand the material.